ISSAQUAH, WASHINGTON / RankWire.AI / – Costco has increased the online retail price of its Kirkland Signature full synthetic motor oil to $57.99 for a 10-quart bundle. This package includes two 5-quart bottles and spans multiple common viscosity grades. Additionally, Costco has implemented a purchase cap on the product, restricting members to buying no more than two units per transaction within a seven-day window. This limitation is visible on select Kirkland Signature motor oil listings on the company’s website.
Compared to roughly a year ago, this new price represents a significant hike. During that period, the same quantity was sold for approximately $30. Costco currently lists various Kirkland full synthetic formulations at $57.99 online, including 5W-30, 5W-20, and 0W-20. Prices at physical warehouse locations can differ from online prices and may vary by region. Each package provides 10 quarts, making this change particularly noteworthy for customers purchasing oil for regular vehicle maintenance.
The purchase restrictions extend beyond Kirkland motor oils to include several Mobil 1 products available through Costco. Mobil 1 is a brand owned by ExxonMobil and is among the most recognizable synthetic motor oils in the United States. Current limits for six-packs of one-quart bottles are set at five units per membership. These affected listings encompass both standard and high-mileage formulations across multiple viscosity grades. Consequently, these restrictions impact not only Costco’s private-label oil but also a major national lubricant brand.
Limits on purchases extend beyond Kirkland motor oils
Production of synthetic motor oils relies heavily on refined base oils and additives that meet current engine protection standards. Group III base oils are a critical component of many synthetic lubricants. The United States sources a significant portion of these materials from overseas suppliers. Many of these are supplied by producers in the Persian Gulf, which account for a large share of global Group III output. Recent disturbances in Middle East energy markets have caused supply shortages of various petroleum products and refining inputs used across the lubricant industry.
Meanwhile, crude oil prices stayed above $100 a barrel in mid-September. Brent crude was trading near $107.82 on September 16, while West Texas Intermediate hovered around $104.86. The energy markets continue to reflect ongoing disruptions in major Middle East production and shipping routes. Traffic through the Strait of Hormuz remains significantly below typical levels. Additionally, Saudi Arabia’s Red Sea export infrastructure has faced interruptions, further straining regional petroleum supplies.
The synthetic oil sector experiences broader supply constraints
Costco’s impacted Kirkland products include grades suitable for numerous passenger cars, SUVs, and light trucks. The retailer states that these oils protect against engine wear and help prevent thermal breakdown. Several formulations meet API SP and ILSAC GF-6A standards, which address engine cleanliness, fuel efficiency, and wear protection. The Mobil 1 listings on Costco’s site also feature various standard, fuel-economy, and high-mileage options.
Costco has not provided an extensive public explanation for the increased Kirkland oil prices or the new purchase restrictions. Its online listings currently show the $57.99 price point along with the two-unit purchase limit for certain products. Meanwhile, separate Mobil 1 product pages still display a five-unit limit per membership for multiple formulations. These changes come amid rising crude oil prices and tighter lubricant supplies, with Costco’s posted limits offering members clear guidance on current purchasing policies and product availability.